When NATO released commercial satellite images on April 10 showing a buildup of Russian forces at Novocherkassk and other towns along the border with Ukraine, a senior Russian military official said the photos actually showed military drills in the area in August 2013.

NATO said the claim was "categorically false," and a new analysis by the AAAS Geospatial Technologies and Human Rights Project of satellite images from the same time period and locations reinforces NATO's case.

As part of a continuing look at the crisis between Ukraine and Russia, the AAAS team acquired multiple high-resolution images of southwestern Russia and eastern Ukraine collected by DigitalGlobe, the same commercial vendor of satellite images that NATO used.

The images confirm NATO's findings and show that the Russians have deployed hundreds of military vehicles, tents, supplies and logistics equipment to areas near Belgorod and Novocherkassk that were empty fields in late 2013. In images taken from 22 March to 26 March, the AAAS analysts were able to watch additional reinforcements arrive at the site. "The claim that no build-up is taking place is inconsistent with the observations of this investigation," the AAAS report states.

Near Kuzminka, an area that appeared as a patchwork of farm fields bordered by rows of trees in October, 2013, there is now a large encampment of tents, trucks and armored vehicles. The fields are crisscrossed by a dense web of heavy vehicle tracks suggesting that the forces have been doing military exercises.

In an image from July 2012, a site near Novocherkassk that now serves as a tank depot is surrounded by trees that are in full leaf. Images obtained by AAAS of the site on March 27— the same date as the image released earlier by NATO-shows the trees to be almost completely bare as expected during very early spring.

The report notes that "biological evidence in the form of seasonal foliage is entirely consistent with the acquisition dates reported by NATO via DigitalGlobe." The images examined by AAAS and those released by NATO are consistent in their depiction of the landscape and, the report says, and "in light of these observations, the claim that the imagery depicts exercises that took place in summer of 2013 lacks credibility."